KR20100046817A - Gasoline direct injection engine - Google Patents

Abstract

PURPOSE: A gasoline direct injection engine is provided to spray the fuel of the high pressure sprayed from an injector without interference by forming an incline on the upper side of a combustion chamber wall in which a nozzle of an injector is open. CONSTITUTION: A gasoline direct injection engine comprises a combustion chamber(C), an intake port(210), an exhaust port(220), an intake valve(211), and an exhaust valve(221), an injector(300), an ignition plug(P), and an incline. The intake port and the exhaust port are communicated with the combustion chamber. The intake valve and the exhaust valve open and close the intake port and the exhaust port. The injector sprays the fuel on the combustion chamber. The ignition plug lights a mixer inside the combustor.

Description

Gasoline Direct Injection Engines {GASOLINE DIRECT INJECTION ENGINE}

The present invention relates to an engine, and more particularly, to a gasoline direct injection (GDI) engine that directly injects fuel into a combustion chamber, and more particularly, to interference of fuel injected from an injector of a GDI engine. It is about the GDI engine which minimized.

Recently, a gasoline direct injection (GDI) engine has been developed that directly injects fuel into the combustion chamber.

In the GDI engine, when the intake valve is opened, air is sucked from the intake port into the combustion chamber and compressed by the piston, and the fuel is directly injected from the engine to the high pressure air.

That is, high pressure air and fuel in a spray state are mixed in the combustion chamber, and the mixer reaches the ignition plug to ignite and ignite to obtain driving force, and the exhaust gas combusted when the exhaust valve is opened is discharged to the exhaust port.

In addition, the GDI engine makes it possible to perform ultra-thin combustion because homogeneous combustion is possible by injecting fuel into the combustion chamber during the intake stroke to form a uniform mixer.

In addition, it has the advantage of improving the fuel economy of the engine and at the same time reduce the emissions of CO ₂ .

The GDI engine having such an advantage injects air from the intake port into the combustion chamber at the time of opening the intake valve in the intake stroke of the piston and simultaneously performs fuel injection on the intake air.

At this time, a mixer dispersed throughout the combustion chamber is formed, and the mixer is ignited by the spark plug, and the mixer dispersed throughout the combustion chamber is homogeneously burned.

Injectors are installed to inject fuel at high pressure from the GDI engine into the combustion chamber.

The injector of GDI engine should be injected into the combustion chamber without interfering with surrounding fuel. The injector is installed at the combustion chamber interface on the lay-out.

In addition, the injection hole opened at the end of the injector and into which the fuel is injected is opened into the combustion chamber.

At this time, the high-pressure injection of the fuel is essential, so it must be injected into the combustion chamber without interference from the surroundings.

However, since the injection hole is inevitably exposed to the combustion chamber, since the vicinity of the injection hole of the injector is exposed to the high temperature combustion gas during the interference of the surroundings and the operation of the engine, carbon is accumulated or deterioration near the injection hole.

As a result, problems such as a decrease in the flow rate of the fuel injected from the injector and a deterioration of the fuel spraying shape occur.

Therefore, the design shape in which the injector is installed at the combustion chamber interface influences the operation performance of the engine.

Therefore, the present invention was created to solve the above problems, and an object of the present invention is to improve the operation performance of the GDI engine by minimizing the interference to the high-pressure fuel injected from the injector.

Gasoline direct injection engine according to an embodiment of the present invention for achieving this object is a combustion chamber;

An intake port and an exhaust port communicating with the combustion chamber;

An intake valve and an exhaust valve for opening and closing the intake port and the exhaust port;

An injector for injecting fuel into the combustion chamber;

An ignition plug that ignites the mixer inside the combustion chamber; And

An inclined surface in which the upper surface of the combustion chamber wall surface in which the injection hole of the injector is opened is cut into a wedge shape;

Characterized in that it comprises a.

In particular, the angle of the inclined surface is preferably 5 to 30 with respect to the horizontal line.

In addition, the area of the inclined surface is preferably set to 80 to 220% with respect to the cross section of the injection port of the injector.

As described above, according to the gasoline direct injection engine according to the present invention, when the high pressure fuel is injected from the injector into the combustion chamber, the pressure loss is reduced by minimizing the interference with the high pressure fuel, thereby improving the operation performance of the GDI engine.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view showing a gasoline direct injection engine according to an embodiment of the present invention, Figure 2 is an enlarged view of a portion A of FIG.

As shown in Figure 1 and 2, the GDI engine according to an embodiment of the present invention is a cylinder block 100 is assembled to the lower portion of the cylinder head, it is fastened by a plurality of fastening bolts (not shown).

The cylinder block 100 is provided with a plurality of cylinder bores 110 (only one cylinder bore is shown in the drawing), and the piston 130 is installed on each cylinder bore 110 so as to slide.

The crankshaft (not shown) is supported to rotate below the cylinder block 100, and each piston 130 is connected to the crankshaft through a connecting rod (not shown).

The combustion chamber C is composed of a cylinder bore 110 formed in the cylinder block 100, a lower surface of the cylinder head 200, and a space formed by the piston head 131. It is formed as a roof shape of the inclined polygon so that the center part is not high.

The intake port 210 and the exhaust port 220 face the upper portion of the combustion chamber C, that is, the lower surface of the cylinder head 200.

The intake valve 211 and the exhaust valve 221 are positioned with respect to the intake port 210 and the exhaust port 220, respectively.

The intake valve 211 and the exhaust valve 222 are supported to reciprocate in the axial direction by respective stem guides (not shown) fixed to the cylinder head 200 and at the same time by the respective valve springs (not shown). The intake port 210 and the exhaust port 220 are elastically supported.

In addition, although the intake valve 211 and the exhaust valve 221 are not shown as a technical configuration that can be commonly applied, one end of the roller rocker arm is connected to the upper end, and the other end of the roller rocker arm is the cylinder head 200. It is connected to a rush adjuster fixed to the intake cam shaft, and the intake cam of the intake cam shaft and the exhaust cam shaft of the exhaust cam shaft are in contact with each roller rocker arm.

Accordingly, when the intake cam shaft and the exhaust cam shaft rotate in synchronization with the engine, the intake cam and the exhaust cam operate the roller rocker arm, and each intake valve and the exhaust valve move at a predetermined timing. It is possible to open and close and communicate the intake port and the combustion chamber, the combustion chamber and the exhaust port, respectively.

On the side of the combustion chamber C, that is, the lower surface of the cylinder head 200 on the intake port side, an injector 300 for injecting fuel directly into the combustion chamber C is mounted.

In addition, an ignition plug P is attached to the center of the ceiling of the combustion chamber C, that is, the lower surface of the cylinder head 200 between each intake port 210 and each exhaust port 220.

Although not shown in the drawing, the electronic control unit (ECU) is installed in the vehicle, so that the fuel injection amount, injection timing, and ignition timing of the injector 300 can be controlled using the ECU. The fuel injection amount, the injection timing, the ignition timing, and the like can be determined based on the engine operation state such as the detected intake air amount, engine speed, throttle opening, and the like.

In addition, in one embodiment of the present invention, the injector 300 is opened into the combustion chamber C, and the inclined surface cut into a wedge shape around the injection port 310 of the injector 300, that is, the upper wall surface of the combustion chamber C. 400 is formed.

That is, the inclined surface 400 is formed in an oblique form with respect to the traveling direction of the high-pressure fuel injected from the injector 300.

At this time, the angle θ of the inclined surface 400 is preferably formed within the range of 5 to 30 degrees with respect to the horizontal line.

In addition, the cut processed area of the inclined surface 400 is preferably 80 to 220% of the cross-sectional area of the injection hole 310 of the injector 300.

The inclined surface 400 having the above shape is a shape in which high-pressure fuel injected from the injector 300 can be injected without surrounding interference, and in addition, the injection hole 310 of the injector 300 has at least the combustion chamber C wall. It should be formed within a range that does not protrude beyond the boundary.

That is, as shown in FIG. 3, the operation performance of the engine may be improved by minimizing interference with a peripheral portion that may be generated when high pressure fuel is injected from the injection hole 310 of the injector 300.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and easily changed and equalized by those skilled in the art from the embodiments of the present invention. It includes all changes to the extent deemed acceptable.

1 is a cross-sectional view of a gasoline direct injection engine according to an embodiment of the present invention.

2 is an enlarged view of a portion A of FIG. 1;

* Explanation of Major Parts Used in Drawings *

100: cylinder block 110: cylinder bore

130: piston 131: piston head

200: cylinder head 210: intake port

211: intake valve 220: exhaust port

221: exhaust valve 300: injector

310: injection hole 400: inclined surface

C: combustion chamber P: spark plug

Claims (3)

combustion chamber; An intake port and an exhaust port communicating with the combustion chamber; An intake valve and an exhaust valve for opening and closing the intake port and the exhaust port; An injector for injecting fuel into the combustion chamber; An ignition plug that ignites the mixer inside the combustion chamber; And An inclined surface which is located on an upper surface of a combustion chamber wall surface at which the injection hole of the injector is opened and is cut into a wedge shape; Gasoline direct injection engine comprising a. The method of claim 1, The angle of the inclined surface is a gasoline direct injection engine, characterized in that 5 to 30 degrees with respect to the horizon. The method of claim 1, The cross-sectional area of the inclined surface is a gasoline direct injection engine, characterized in that formed in the range of 80 ~ 220% relative to the cross section of the injection port of the injector.

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